zep Posted November 30, 2021 Share Posted November 30, 2021 Hey all, My search for long toyota G-series axles has led me find that the longest ones come from 4x4s like a Surf. I should be able to swap from 6 stud to 4 stud without too many problems, but the issue is that they have a 101.6mm centrebore which is way too large. Does anyone have any experience in machining this down? I have my discs mounted behind the WMS so I am only concerned with getting the wheels on. Cheers Quote Link to comment Share on other sites More sharing options...
kpr Posted November 30, 2021 Share Posted November 30, 2021 Yeah easy. That part of the axles isn't hardened. You'll also need to watch out with the 6 stud ones the back side of axle flange too big to fit a smaller pcd. So will need to be machined smaller to fit the studs in. I recall way back my cert guy wasn't happy for that part of axle to be machined. I don't know If thats actually a thing or not. But maybe worth finding out first. Some of the hiace ones are also quite long Quote Link to comment Share on other sites More sharing options...
cletus Posted November 30, 2021 Share Posted November 30, 2021 @johnny.race would probably know what's involved I have not done it myself but it's common to use 6 stud axles in conversions for rotaries to make a 4 stud Quote Link to comment Share on other sites More sharing options...
cletus Posted November 30, 2021 Share Posted November 30, 2021 I think some of the reasons for using 6 stud axles are the holes are further away from the 4x110 or whatever a Mazda is compared to a 5 stud axle And they are cheap and easy to find 1 Quote Link to comment Share on other sites More sharing options...
zep Posted November 30, 2021 Author Share Posted November 30, 2021 1 hour ago, kpr said: Some of the hiace ones are also quite long I've heard this. Any ideas which ones? There are 5 stud 2WD and 6 stud 4X4 Hiaces. Hard to get a wrecker to go out and measure the wms to wms for me! 52 minutes ago, cletus said: I think some of the reasons for using 6 stud axles are the holes are further away from the 4x110 or whatever a Mazda is compared to a 5 stud axle And they are cheap and easy to find That's good to know that people use them. Keen to know about that back side machining too. Quote Link to comment Share on other sites More sharing options...
Raizer Posted November 30, 2021 Share Posted November 30, 2021 Maybe wide body 200 series HiAce? Even the 2wd 200s are 6 stud from memory. Quote Link to comment Share on other sites More sharing options...
Popular Post johnny.race Posted November 30, 2021 Popular Post Share Posted November 30, 2021 Talofa gents. The longest axles that still make use of the conventional style Hilux wheel bearing holder housing register are the KUN's. You be wanting the early KUN that is sans ABS. 5 stud or 6 name your poison - they are both XL in length compared to the earlier stuff. You'd be doing well to get a 6 stud Hiace axle to work with a Hilux housing - Toyota changed the OD of the wheel bearing. Those 6 stud Hiaces are truly a HD setup and are bigger than a normal Lux.. The reason 5 stud axles are not popular for 4 stud conversions is due to the fact there is no room on the flange face to fit 4 extra holes. You can but it looks dodgy. You can weld but that can be a dodgy proposition too due to this practice being frowned upon by some cert inspectors. So as @cletus pointed out - enter the 6 stud. The vintage and model of vehicle the 6 stud axle originally came from determines what style center it comes with. Look at the dirty great sink hole in the center of the axle on the left hand side compared to the other. All 6 stud axles are shallow in the middle and you need to be leaving as much OEM material in place as possible to give yourself every chance of obtaining a hubcentric fit of the rotor. This feat is made more difficult due to the fact most rotors having a big arsed bevel on the inner face of the hat. You get one shot at it. Fuck it up, the rotor rattles around and the axle is basically scrap. There isn't even enuff meat in the remaining center to tack a ring on with any certainty. You can but well you run the chance of having a shit load of time and effort in a custom width narrowed axle only for it to fail at cert inspection time. You are after this. The other challenge is the forging chamfer/bevel on the back face of the axle. There are basically 2 options to seat the head of a wheel stud being used in a smaller PCD than the OEM Hilux 6 stud PCD - counterbore or lessening the OEM chamfer/bevel dia. Who's got a counterbore setup in their shed on a machine rigid enuff to hold an axle to no/nada/zilch movement. Yeah nah, The diameter is brought down to the OEM 5 stud size leaving a beautifully big and generous chamfer cut. Like this. In everything that you do with axles - you only want to be removing what you have to. Hilux's have generous axle flange thickness. This is one of their strengths. I do my best to play to it. Cheers. 11 5 Quote Link to comment Share on other sites More sharing options...
zep Posted November 30, 2021 Author Share Posted November 30, 2021 Wow! Thanks @johnny.race So it's not quite as easy as I had been told. My current diff is one of the 1410mm wide ones. I'm essentially looking for axles that are the splines plus the tapered area longer, so I can cut it all off and respline at my required length. Do you think there is enough material in the mounting face centre to machine a 6 stud down to 68.3mm from the stock 101.6mm? As I mentioned above, my rotors are currently mounted behind the flange face. I need to pull them off and see how this was achieved as I didn't do it personally. Could be some machine trickery behind there. Is there any reason not to just grab an entire 6 stud hiace housing and axles then, if they are more butty? Will my existing hilux diff head work with this? 1 Quote Link to comment Share on other sites More sharing options...
mjrstar Posted December 1, 2021 Share Posted December 1, 2021 Does a 6 stud to 4 stud hubcentric bolt on adapter solve your problem? That's what I did on my kp with hilux diff. I used a land cruiser disc and rx7 caliper in the braking department then used 2 left hand side r30 skyline handbrake cables. Quote Link to comment Share on other sites More sharing options...
zep Posted December 1, 2021 Author Share Posted December 1, 2021 12 minutes ago, mjrstar said: Does a 6 stud to 4 stud hubcentric bolt on adapter solve your problem? That's what I did on my kp with hilux diff. I used a land cruiser disc and rx7 caliper in the braking department then used 2 left hand side r30 skyline handbrake cables. I don't think so. I'm trying to shorten the diff and the space that the adapter would take up would mean I need to go in even further. 23 hours ago, johnny.race said: The longest axles that still make use of the conventional style Hilux wheel bearing holder housing register are the KUN's. You be wanting the early KUN that is sans ABS. 5 stud or 6 name your poison - they are both XL in length compared to the earlier stuff. Is there a KUN equivalent of a Hiace? There are heaps of them at wreckers. Quote Link to comment Share on other sites More sharing options...
mjrstar Posted December 1, 2021 Share Posted December 1, 2021 Sweet, I thought you might get away with the shorter easier to find axle? Quote Link to comment Share on other sites More sharing options...
CUL8R Posted December 1, 2021 Share Posted December 1, 2021 In my experience the Late 80's to Early 2000's Hiace are the same as your Hilux's - as in the splines, with drum brakes standard. They will use the same head and axle flange bolt pattern, however I believe the 5.1 Ratio has a notch in the housing for the larger Crown wheel (in itself that is quite a rare one, much like finding a 3.7 or 3.9) There's different types of housings, a centre style with the axle tubes welded in, and more of a 2 stamped halves housing then welded style if I remember correctly? I used to prefer the Leaf Spring Diffs over say the Hilux Surfs, as it meant less brackets to cut off. I had run a mix of Hiace,Hilux, Hilux Surf, and Prado. I think certain Landcruiser could be used also Johnny race will no doubt set the record straight Quote Link to comment Share on other sites More sharing options...
zep Posted December 1, 2021 Author Share Posted December 1, 2021 Yep, mine is the one with the weld down the centre. It's starting to feel like with the work I will have to do I may as well start again with a Borgwarner or something, as they have heaps of drop in aftermarket heads and probably a lack of annoying axle tapers. Quote Link to comment Share on other sites More sharing options...
kpr Posted December 1, 2021 Share Posted December 1, 2021 what length do you need? have you looked into aftermarket 4wd stuff? maybe something that you dont have to get re-splined Quote Link to comment Share on other sites More sharing options...
mjrstar Posted December 1, 2021 Share Posted December 1, 2021 Maybe not so much for a road car but one thing that intrigued me for a rwd race car like a starlet or escort would be to drop in a sprint car style quick change rear end.. There will be a reason I haven't thought of why this is a dumb idea, but man you can pour some cash into shortening an oem diff if you are outsourcing all the work. Quote Link to comment Share on other sites More sharing options...
zep Posted December 1, 2021 Author Share Posted December 1, 2021 9 hours ago, kpr said: what length do you need? have you looked into aftermarket 4wd stuff? maybe something that you dont have to get re-splined I did initially when I was looking for something that was the correct centrebore. At this point I may as well just buy some blanks with extra long spines that can be cut down. Then I can just machine down the centrebore and be done with it. I'll have another look. Quote Link to comment Share on other sites More sharing options...
cletus Posted December 1, 2021 Share Posted December 1, 2021 If you are bolting the disc behind the axle face, do you even need a center spigot on the axle? It's obviously better if the wheel locates on a spigot in the middle , but if you aren't running spacers, and your wheels have tapered nuts, it's not actually a cert requirement, the axle face could be flat I dunno if starting again would be any better, if you have a good hilux diff already, a borg Warner isn't a bad diff but by the time you buy one, rebuild it, get the right ratio and a good lsd, and buy axles it might be more expensive than persevering with what you have Quote Link to comment Share on other sites More sharing options...
zep Posted December 1, 2021 Author Share Posted December 1, 2021 Yeah, you're right. I need to pull my axle out again and measure it up. I have found some axles such as this: https://www.nitro-gear.com/Toyota-8-8-4-Nitro-Chromoly-CTL-Axle-p/axt34060.htm But even cut down to the narrowest I don't think will be short enough. That's good to know about the spigot - I thought they were necessary for ensuring strength. Quote Link to comment Share on other sites More sharing options...
Snoozin Posted December 1, 2021 Share Posted December 1, 2021 4 hours ago, mjrstar said: Maybe not so much for a road car but one thing that intrigued me for a rwd race car like a starlet or escort would be to drop in a sprint car style quick change rear end.. There will be a reason I haven't thought of why this is a dumb idea, but man you can pour some cash into shortening an oem diff if you are outsourcing all the work. That silver KP Starlet at OS Drags last time, had a sprint car Winters in it. Quote Link to comment Share on other sites More sharing options...
kpr Posted December 1, 2021 Share Posted December 1, 2021 @zep that chart i posted was trailgear stuff. if got 2 short side rock assault, would be at a guess 1300 ish wide. which probably too short? Quote Link to comment Share on other sites More sharing options...
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